The present subject matter generally relates to particular flash memory storage applications. More particularly, the present subject matter relates to a method of using flash memory for the storage of metering data. Still further, the present subject matter relates to a method for using flash memory in conjunction with random access memory (hereinafter RAM) for the storage of metering data and maintaining such data despite a loss of power.
Conventional memory systems are well known. Large amounts of data are commonly stored using rotating storage media such as magnetic disk drives. Such systems are slow to recover and store data. Additionally, such systems require large amounts of power and are relatively heavy.
Size constraints of certain existing flash memory systems have limited their typical use to storing programs and constants that are erased and then rewritten in their entirety. In general, such systems are not used to store data because data is typically not changed in its entirety. Instead, data has typically been stored in alternative memory structures, such as EPROMS, EEPROMS, and a variety of RAM structures, which allow the alteration of only a portion of the stored information. Such memory structures, however, are less cost effective than flash memory systems and in the case of certain types of RAM, namely battery-backed RAM, there are additional lifetime costs associated with the maintenance of the battery.
Early flash memory systems consisted of a single storage block for storing information. Such individual storage locations cannot be rewritten to until such time as they are erased. The erasure of stored information in such memory, however, cannot occur on a partial basis. Instead, erasure of such information must be complete at which point all previously stored information is lost.
Conventional flash memory systems have been developed such that they are more useful in storing data. Such flash memory has been segmented into large numbers of smaller storage locations. These most recent flash memory systems are flexible enough to store data and are ideally suited for use in the storage of metering data. While each of such storage blocks must still be erased in their entirety, such flash memory devices contain enough small storage blocks to satisfactorily maintain stored metering data.
These conventional flash memory systems consume very little power and are relatively fast to operate. New flash memory is also much more cost effective than non-volatile memory such as EPROM, EEPROM, etc. In additional to being more cost effective, such conventional flash memory systems are currently available in higher density arrays than comparable EEPROM and RAM memory systems. As the demand for the storage of more metering data is made in the utility industry, cost savings realized through the use of more efficient and cheaper memory systems will be significant.
While non-volatile memory systems have been used in the past in metering applications, their use is sometimes limited to the storage of constant values and equations for performing calculations that may determine otherwise desired parameters of a meter""s performance or the demand therethrough. One such example of the limited use of such non-volatile memory structures in metering applications is U.S. Pat. No. 5,548,527, which is fully incorporated herein for all purposes by present reference thereto.
Similarly, U.S. Pat. No. 4,361,877, provides for the use of non-volatile memory to store a set of data measurements obtained over time and compiled within an associated memory. Such non-volatile memory is then removed for further processing to obtain the desired data and replaced by a new memory structure.
Utilizing a battery-backed RAM memory to store data, as well as to attempt to preserve such data during power outages to ensure the continuity of the usage data despite the power loss is the aim of U.S. Pat. No. 4,335,447. Both U.S. Pat. Nos. 4,335,447 and 4,361,877 are fully incorporated herein for all purposes by present reference thereto.
Other patents referencing the use of various types of memory structures to handle and store utility metering data include U.S. Pat. Nos. 4,783,623; 4,792,677; 4,852,030; 5,270,639; 5,311,068; 5,377,114; 5,473,322; 5,918,380; 5,994,892; 6,006,212; and 6,163,276.
While useful for their purposes, none of the above references solves the problems addressed by the presently disclosed technology, namely, the need for a cost-effective, efficient, non-volatile memory structure used to store metering data while not requiring replacement.
It is, therefore, desirable to provide a method for using a more cost-effective memory to store metering data. Still further, it is desirable to provide a method of using such memory in conjunction with an additional associated memory structure as a way to store metering data and maintaining such data despite a loss of power. Finally, it is desirable to utilize a mutli-segmented flash memory for storing metering data in conjunction with an associated memory structure for use in alteration and maintenance of the metering data during periods when measurements are taken and during a potential power loss to the meter.
The present subject matter recognizes and addresses various of the foregoing limitations and drawbacks, and others, concerning the storage of measured metering data and the maintenance of that data during a loss of power. Therefore, the presently disclosed technology provides a new method of storing metering data into faster, more cost effective non-volatile flash memory structures. Still further, the present subject matter provides a new method of using flash memory in conjunction with RAM memory for storing metering data and maintaining such data despite a loss of power.
It is, therefore, a principle object of the disclosed technology to provide a method for using non-volatile flash memory for storing information. More particularly, it is an object of the present subject matter to provide a method for using such memory in association with RAM memory for storing and maintaining data.
It is a further object of the present subject matter to provide a method of protecting metering data during a loss of power. More particularly, it is an object of the present subject matter to provide a method of protecting metering data during a loss of power using a combination of volatile and non-volatile memory structures.
It is still another object of the presently disclosed technology to provide a method for storing metering data that is cost effective. In such context, it is a further object of the present technology to provide a more flexible and efficient method for the storage of metering data.
Additional objects and advantages of the present subject matter are set forth in, or will be apparent to those of ordinary skill in the art, from the detailed description as follows. Also, it should be further appreciated that modifications and variations to the specifically illustrated and discussed steps, features, and materials, or devices hereof may be practiced in various embodiments and uses of the disclosed technology without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitutions of equivalent steps, elements, features, and materials for those shown or discussed, and the functional or positional reversal of various steps, parts, features, or the like.
Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of the present subject matter may include various combinations or configurations of presently disclosed steps, features, elements, or their equivalents (including combinations of features or configurations thereof not expressly shown in the figures or stated in the detailed description).
These and other features, aspects and advantages of the present technology will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the present subject matter and, together with the description, serve to explain the principles of the technology.